(5R)-6-benzyloxycarbonylmethylene-3,3-dimethyl-7-oxo-(5rH)-4-thia-1-aza-bicyclo[3.2.0]heptane-2c-carboxylic acid 2,2,2-trichloro-ethyl ester
(5R)-6t-benzyloxycarbonylmethyl-3,3-dimethyl-7-oxo-(5rH)-4-thia-1-aza-bicyclo[3.2.0]heptane-2c-carboxylic acid 2,2,2-trichloro-ethyl ester
(5R)-6t-carboxymethyl-3,3-dimethyl-7-oxo-(5rH)-4-thia-1-aza-bicyclo[3.2.0]heptane-2c-carboxylic acid 2,2,2-trichloro-ethyl ester
N-(2-hydroxy-2-phenylethyl)formamide